Engine starter control



March 21. 1939. MAURER 2,151,041

ENGINE STARTER CONTROL Original Filed April 16, 1955 I 3\ 0 11 44 1 H w17 [:1 m I III INVENTOR.

Milne/s5: v 1 Pall/6 4%. mm

6 MW BY Md.

Patented Mar. 21, 1939 UNITED STATES PATENT orrlcr.

ENGINE STARTER CONTROL aware Original application April 16, 1935, SerialNo. 16,643. Divided and this application December 24, 1936, Serial No.117,547

6 Claims.

controls and more particularly to a device for energizing by progressivesteps an engine starter of the automatic mesh and demesh type so as tosecure engagement of the starting mechanism prior to the fullenergization of the starting motor.

This application is a division of application Serial Number 16,643,filed April16, 1935, Patent Number 2,073,645.

In starting devices of the automatically meshing and demeshing type,energization of the starting motor is caused to move a pinion intoengagement with an engine gear and thus establish a driving connectionbetween the starting motor and engine, which driving connection isautomatically interrupted when the engine starts, by theoverrunningaction of the engine gear which returns the starting pinionto idle position. It will be readily understood that the running startof the motor prior to the engagement of the pinion with the engine gearpermits considerable kinetic energy to be stored up in the startingmotor and connected parts, which kinetic energy is applied to initiatethe rotation of the engine gear.

In certain very heavy duty installations such as large Diesel engineunits, where powerful starting motors are energized from batteries ofcomparatively high voltage with very large current consumption, it hasbeen found that the amount of kinetic energy so stored up by the runningstart is so large that the parts of the drive when properly designed forthe most efiicient cranking operation may be seriously overloaded whenthe starter gearing is initially engaged.

It has therefore been suggested to energize the starting motor with lessthan the full battery voltage during the meshing operation and then toapply the full battery voltage to the motor after the driving connectionhas been established, the initial energization being merely suflicientto secure the proper automatic engagement of the drive without storingup unnecessarily large amounts of kinetic energy in the motor armatureand its associated parts.

It is an object of the present invention to provide a novel startercontrol of the type stated which is simple and economical inconstruction and reliable and eificient in operation.

It is another object to provide such a starter control which positivelyprevents premature energization of thestarting motor to its fullcapacity.

It is another object to provide such a device in which the parts resetthemselves during cranking (Cl. 290-38) The present invention relates toengine starter so that a restart is controlled similarly to an orig-'inal start.

It is another object to provide such a device in which a resistor isused to modify the initial actuation of the starting motor, and the sameelement functions to control the time delay prior to full energizationthereof,

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawing in which:

Fig. l is a semi-diagrammatic illustration of one preferred embodimentof the invention showing the parts in normal or idle position; and

Fig. 2 is a similar view showing the cranking position.

In the embodiment of the invention illustrated, a two-stage manuallyoperated switch is employed for controlling the starting operation. Ashere illustrated, the starting circuit originally includes battery 9,lead 2, manual switch 3, lead 4, resistor 5, lead 6 and starting motorSM, resistor 5 being of such value as to cause energization of thestarting motor only to a suitable degree for engaging the startinggearing. There is also provided a bridging circuit 7 forshort-circuiting the resistor 5, which bridging circuit is controlled bya magnetic switch 8 comprising a solenoid 9.

Manual switch 3 comprises fixed contacts I I and I2 and a bridgingcontact l3 for completing the initial starting circuit. This switch alsoincludes a second pair of fixed contacts l4 and 45 which are closed byfinal movement of the bridging contact l3 to thereby complete a circuitfrom battery lead 2 through lead [6 to solenoid 9 which is grounded asindicated at H.

Means are provided for initially preventing movement of the manualswitch 3 suflicient to close the circuit of solenoid 9, here illustratedin the form of a latch member l8 movable into and out of the path ofbridging contact l3 by means of a bimetal strip l9 suitably anchored at2| and arranged to be heated by the resistor 5 when current is passedtherethrough. The latch I8 is in the path of the bridging contact l3when the bimetal is at normal temperatures, and is moved out of the pathof said contact to permit full traversal thereof when the bimetal isheated to a predetermined temperature. v

In the operation of this embodiment of the invention, actuation by theoperator of the manual switch 3 causes contact 13 to connect fixedcontacts H and I2, thus completing the initial starting circuit throughresistor 5 to the starting motor SM whereby the latter is energized tocause engagement of the starting gearing. Further parts in travel ofcontact i3 is initially prevented by latch l8. Alter a predeterminedtime interval, resistor I heats up the bimetal I l sumciently towithdraw the latch l8 from the path of contact l3, whereupon iurtheractuation of the manual switch causes bridging of contacts l4, l5 bycontact l3, thereby energizing solenoid 9 and causing closure ofmagnetic switch 8. The resistor 5 is thereby short-circuited and thestarting motor fully energized to crank the engine. Resistor 5 andbimetal I! are thus permitted to cool off, and when the manual switch 3is released as the engine starts, the parts return to their normalpositions as illustrated in Fig. 1.

Although but one embodiment of the invention has been shown anddescribed in detail, it will be understood that other embodiments arepossible and various changes may be made in the arrangement andconstruction of the parts without departing from the spirit of theinvention as defined in the claims appended hereto.

What is claimed is:

1. In an electrical starting system for internal combustion engines, abattery, a starting motor, a resistor, a circuit including a manuallyoperable switch having two sets of contacts, closure of the first setcompleting a circuit through the resistor to the starting motor, andclosure of the second set causing the resistor to be short-circuited,and a thermostaticlatch for preventing closure or the second set ofcontacts until the resistor has been heated to a predetermined degree.

2. In an electrical starting system for internal combustion engines, abattery, a starting motor, a resistor, a. circuit including a manuallyoperable switch having two sets of contacts, closure of the first setcompleting a circuit through the resistor to the starting motor, andclosure of the second set causing the resistor to be shortcircuited, alatch normally preventing operation or the switch to close the secondset of contacts, and thermostatic means heated by said resistor forwithdrawing said latch.

3. In a starting system for internal combustion engines, a startingcircuit including a two-stage switch, means whereby operation of theswitch to the first stage causes partial energization of the startingsystem, means whereby operation of the switch to the second stage causesfull energization of the starting system, means preventing operation 0!the switch to its second stage, and thermostatic means heated byoperation of the switch to its first stage for rendering inoperativesaid preventing means.

4. In a starting system for internal combustion engines, a startingcircuit including a resistor, a two-stage switch, means whereby thefirst operation of the switch closes said circuit through the resistor,and further operation thereof shorts out the resistor, and thermostaticmeans, controlled by heat from said resistor, for preventing suchfurther operation.

5. In a starting system for internal combustion engines, a startingcircuit including a battery, a starting motor with means for engagingand cranking the engine to be started, a manually operable switch and aresistor adapted to limit the energization of the motor to a valuesuitable for effecting engagement of the cranking means. means wherebyinitial operation of said switch closes the motor circuit through theresistor, means whereby further operation of the switch causes fullenergization of the starting motor, means for preventing such furtheroperation of the switch, and means responsive to closure of the motorcircuit through the resistor for a pre determined time for releasingsaid preventing means.

6. In a starting system for internal combustion engines of the automaticmeshing type, a starting circuit including a two-stage switch, meanswhereby operation of the switch to the first stage causes partialenergization of the starting system for meshing the starter gearing,means whereby operation of the switch to the second stage causes fullenergization of the starting system to crank the engine, means forinitially preventing such operation to the second stage, and meansactuated by the flow of current through the switch in its first stageposition for a predetermined time, to render said preventing meansinoperative.

PAUL H. MAU'RER.

